Venous thromboembolism (VTE)

Venous thromboembolism (VTE) refers to a blood clot forming in a vein, most often in the leg (deep vein thrombosis) or travelling to the lungs (pulmonary embolism). Fertility treatment, particularly ovarian stimulation and ovarian hyperstimulation syndrome, along with pregnancy itself, is associated with a modestly increased risk of VTE compared with the general population, in addition to other individual risk factors such as obesity, immobility, smoking or a personal or family history of clots. Symptoms that need urgent medical attention include swelling, pain, redness or warmth in one leg, and breathlessness, chest pain or coughing up blood, which can indicate a clot has reached the lungs. Anyone with these symptoms during or after fertility treatment should contact their clinic immediately or attend the nearest hospital emergency department without delay, as pulmonary embolism can be life-threatening. Clinics assess individual VTE risk factors before and during treatment, and may recommend measures such as staying mobile, adequate hydration, and, in higher-risk individuals, other preventive measures decided by the treating team; any personal or family history of blood clots should be disclosed to the clinic at the start of treatment.

Also known as: thrombosis, VTE, deep vein thrombosis, blood clot after ivf

Last reviewed: 9 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.